pressure pulsation at rated point

[Rasoul1250]

Hi all

I started LMV322 pump and contentiously open the discharge valve from 25 % to 70 %, all things are OK. Note that in this condition, flow is in rated point. Once i want to open the discharge valve a little more,discharge pressure Gage and Amper monitoring fluctuated and by returning to its previous state (70%), the problem is not solved.

process Conditions:
suction pressure=5.5 bar g
vapor pressure= 4.5 bar a
Q=2300 kg/h equal to design point
Liquid: Buten

the question is "What can result in pressure pulsation!?" and how can solve it?!.
Has anyone else experienced similar problem as I have described?

 

[bellowsmfg]

This is very open without knowing what the rest of the system it like. Can you start with describing how the piping layout is on the suction and discharge of the pump?

Bellows Manufacturing and Research, Inc.

https://bellowsmfg.com

 

[1gibson]

Sounds like an NPSH problem, find the NPSH required on the pump curve. It is probably fine at the rated point, but at higher flow you may not have enough NPSH available to operate.